package com.framework.utils;

import java.math.BigInteger;
import java.net.URLEncoder;
import java.nio.charset.StandardCharsets;
import java.util.*;

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.spec.SecretKeySpec;

import org.apache.commons.codec.binary.Base64;

import org.apache.commons.lang.StringUtils;
import sun.misc.BASE64Decoder;

/**
 * 功能描述: AES的加密和解密
 *
 * @author ck
 * @date 2018/8/27 20:18
 */
public class AesUtil {

	//算法
	private static final String ALGORITHMSTR = "AES/ECB/PKCS5Padding";
	
	//秘匙
	private static final String AES_KEY = "13MKcb60tjk308Us";

	/**
	 * aes解密
	 * @param encrypt  内容
	 * @return
	 * @throws Exception
	 */
	public static String aesDecrypt(String encrypt) {
		try {
			return aesDecrypt(encrypt, AES_KEY);
		} catch (Exception e) {
			e.printStackTrace();
			return "";
		}
	}

	/**
	 * aes加密
	 * @param content
	 * @return
	 * @throws Exception
	 */
	public static String aesEncrypt(String content) {
		try {
			return aesEncrypt(content, AES_KEY);
		} catch (Exception e) {
			e.printStackTrace();
			return "";
		}
	}

	/**
	 * 将byte[]转为各种进制的字符串
	 * @param bytes byte[]
	 * @param radix 可以转换进制的范围，从Character.MIN_RADIX到Character.MAX_RADIX，超出范围后变为10进制
	 * @return 转换后的字符串
	 */
	public static String binary(byte[] bytes, int radix){
		return new BigInteger(1, bytes).toString(radix);// 这里的1代表正数
	}

	/**
	 * base 64 encode
	 * @param bytes 待编码的byte[]
	 * @return 编码后的base 64 code
	 */
	public static String base64Encode(byte[] bytes){
		return Base64.encodeBase64String(bytes);
	}

	/**
	 * base 64 decode
	 * @param base64Code 待解码的base 64 code
	 * @return 解码后的byte[]
	 * @throws Exception
	 */
	public static byte[] base64Decode(String base64Code) throws Exception{
		return StringUtils.isEmpty(base64Code) ? null : new BASE64Decoder().decodeBuffer(base64Code);
	}


	/**
	 * AES加密
	 * @param content 待加密的内容
	 * @param encryptKey 加密密钥
	 * @return 加密后的byte[]
	 * @throws Exception
	 */
	public static byte[] aesEncryptToBytes(String content, String encryptKey) throws Exception {
		KeyGenerator kgen = KeyGenerator.getInstance("AES");
		kgen.init(128);
		Cipher cipher = Cipher.getInstance(ALGORITHMSTR);
		cipher.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(encryptKey.getBytes(), "AES"));

		return cipher.doFinal(content.getBytes(StandardCharsets.UTF_8));
	}


	/**
	 * AES加密为base 64 code
	 * @param content 待加密的内容
	 * @param encryptKey 加密密钥
	 * @return 加密后的base 64 code
	 * @throws Exception
	 */
	public static String aesEncrypt(String content, String encryptKey) throws Exception {
		return base64Encode(aesEncryptToBytes(content, encryptKey));
	}

	/**
	 * AES解密
	 * @param encryptBytes 待解密的byte[]
	 * @param decryptKey 解密密钥
	 * @return 解密后的String
	 * @throws Exception
	 */
	public static String aesDecryptByBytes(byte[] encryptBytes, String decryptKey) throws Exception {
		KeyGenerator kgen = KeyGenerator.getInstance("AES");
		kgen.init(128);

		Cipher cipher = Cipher.getInstance(ALGORITHMSTR);
		cipher.init(Cipher.DECRYPT_MODE, new SecretKeySpec(decryptKey.getBytes(), "AES"));
		byte[] decryptBytes = cipher.doFinal(encryptBytes);
		return new String(decryptBytes);
	}


	/**
	 * 将base 64 code AES解密
	 * @param encryptStr 待解密的base 64 code
	 * @param decryptKey 解密密钥
	 * @return 解密后的string
	 * @throws Exception
	 */
	public static String aesDecrypt(String encryptStr, String decryptKey) throws Exception {
		return StringUtils.isEmpty(encryptStr) ? null : aesDecryptByBytes(base64Decode(encryptStr), decryptKey);
	}

	/**
	 * 测试
	 * 前端js将参数加密提交到后台如何解密
	 * 首先获取服务端的私钥:将客户端的公钥加密后获得的结果
	 * 通过服务端的私钥和客户端传递的加密字符串即可实现解密
	 */
	public static void main(String[] args) {
		/*System.out.print(UuidUtil.getUUID());
		String content = "syz778899..";
		System.out.println("加密前：" + content);
		System.out.println("加密密钥和解密密钥：" + AES_KEY);
		String encrypt = aesEncrypt(content, AES_KEY);
		System.out.println("加密后：" + encrypt);
		String decrypt = aesDecrypt(encrypt, AES_KEY);
		System.out.println("解密后：" + decrypt);
		//js加密后的字符串: lkqsgKHH7OkhIa0tISMtuQ==
		String jsData = aesDecrypt("lkqsgKHH7OkhIa0tISMtuQ==", AES_KEY);
		System.out.println("前端数据解密后的值:" + jsData);

		// TODO Auto-generated method stub
				//字典序列排序
		Map<String,String> paraMap = new HashMap<String,String>();
		paraMap.put("price","voNTzVchEyOOZj8lh85l5Oi7TQgAvXxqzSST24a4Ait+4PfZUP7iX/oFN3DSK5XA");
		String url = formatUrlMap(paraMap, false, true);
		System.out.println(url);*/

	}
	
	/**
     * 
     * 方法用途: 对所有传入参数按照字段名的Unicode码从小到大排序（字典序），并且生成url参数串<br>
     * 实现步骤: <br>
     * 
     * @param paraMap   要排序的Map对象
     * @param urlEncode   是否需要URLENCODE
     * @param keyToLower    是否需要将Key转换为全小写
     *            true:key转化成小写，false:不转化
     * @return
     */
    public static String formatUrlMap(Map<String, String> paraMap, boolean urlEncode, boolean keyToLower){
        String buff = "";
        Map<String, String> tmpMap = paraMap;
        try{
            List<Map.Entry<String, String>> infoIds = new ArrayList<Map.Entry<String, String>>(tmpMap.entrySet());
            // 对所有传入参数按照字段名的 ASCII 码从小到大排序（字典序）
            Collections.sort(infoIds, Comparator.comparing(o -> (o.getKey())));
            // 构造URL 键值对的格式
            StringBuilder buf = new StringBuilder();
            for (Map.Entry<String, String> item : infoIds){
                if (StringUtils.isNotBlank(item.getKey())){
                    String key = item.getKey();
                    String val = item.getValue();
                    if (urlEncode){
                        val = URLEncoder.encode(val, "utf-8");
                    }
                    if (keyToLower){
                        buf.append(key.toLowerCase() + "=" + val);
                    } else{
                        buf.append(key + "=" + val);
                    }
                    buf.append("&");
                }
            }
            buff = buf.toString();
            if (buff.isEmpty() == false){
                buff = buff.substring(0, buff.length() - 1);
            }
        } catch (Exception e){
           return null;
        }
        return buff;
    }
}

